Object server PUTs should respect client_timeout

It seems the object server never respected the client_timeout value
since the beginning of Swift. This is normally fine since the proxy does
and will normally hang up on the backends. But if the proxy has a bug or
if there's network issues or whatever, the object server should be smart
enough to enforce this timeout as well.

Our operations guys noticed this problem when older processes would
never exit after a reload. They started investigating and saw that the
object server had open tmp files that hadn't been touched in quite some
time. Sometimes the tmp files didn't even exist anymore since the
reclaimer deletes really old untouched tmp files.

Change-Id: Iba0397203a2dccca4a28a8c8cbfc5a60e429837a
Merge "Object server PUTs should respect client_timeout"